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12-07-2013, 06:14 AM   #31
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We'd like to see your opinion and comparison with DA21

12-07-2013, 06:37 AM - 2 Likes   #32
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Well after first tests :
Lens is bigger than expected but light.
At the 20 mm side, the DA 20-40 is clearly sharper than the DA21 at f3.2 and f4 (haven't yet made further tests at f5.6, but I assume the trend is here). Color rendition is colder. Field curvature is more pronounced on the DA21. There is some AC, same amount as on the DA21. My copy is slightly softer on the right side (my DA21 is slightly softer on the left side). Haven't test the distorsion. Well controlled falloff (less at f2.8 than on the DA21 at f3.2)
At 40 mm compared to the FA43 limited, at f4 as the FA43 is already stopped down a lot, there is a clear advantage for the FA43 but the image is already good wide open.
Stopped down at f5.6, the center clarity and sharpness of the FA43 can't be surpassed, but the 20-40 seems more homogeneous with good sharpness. very low lateral AC.
As a first conclusion, this lens - at least my copy - is a solid performer. By the way, it is a silver copy, my friend at the reseller had one black and one silver copy in stock, she tested both, she find them very close, but the silver was slightly better so I got the silver.
12-07-2013, 07:05 AM   #33
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QuoteOriginally posted by goubejp Quote
Well after first tests :
Lens is bigger than expected but light.
At the 20 mm side, the DA 20-40 is clearly sharper than the DA21 at f3.2 and f4 (haven't yet made further tests at f5.6, but I assume the trend is here). Color rendition is colder. Field curvature is more pronounced on the DA21. There is some AC, same amount as on the DA21. My copy is slightly softer on the right side (my DA21 is slightly softer on the left side). Haven't test the distorsion. Well controlled falloff (less at f2.8 than on the DA21 at f3.2)
At 40 mm compared to the FA43 limited, at f4 as the FA43 is already stopped down a lot, there is a clear advantage for the FA43 but the image is already good wide open.
Stopped down at f5.6, the center clarity and sharpness of the FA43 can't be surpassed, but the 20-40 seems more homogeneous with good sharpness. very low lateral AC.
As a first conclusion, this lens - at least my copy - is a solid performer. By the way, it is a silver copy, my friend at the reseller had one black and one silver copy in stock, she tested both, she find them very close, but the silver was slightly better so I got the silver.
This is sort of the result I was expecting from the lens. I am looking forward to my mine next week. The focal range and WR fits perfectly my hobbies (hiking/backpacking). Please post some photos if you can. I am curious about your comment about the color of the zoom. I already thought the DA primes rendered slightly on the colder side.
12-07-2013, 07:13 AM   #34
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QuoteOriginally posted by goubejp Quote
By the way, it is a silver copy, my friend at the reseller had one black and one silver copy in stock, she tested both, she find them very close, but the silver was slightly better so I got the silver.
Thank you very much for the quick review,
and especially for this last comment,
since it gives a first hint about sample variation.

BTW, for English-speaking readers, "AC" is CA.
(Although the lens has DC! )

12-07-2013, 07:37 AM   #35
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QuoteOriginally posted by lytrytyr Quote
(Although the lens has DC! )
........and is a DA that hopefully has undergone proper QC.
12-07-2013, 07:48 AM   #36
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It has a 55mm filter ring?? Pentax has never produced a lens with this size before, to my knowledge. I do love the Takumar-esque focus ring of this lens.
12-07-2013, 09:11 AM   #37
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QuoteOriginally posted by goubejp Quote
Well after first tests :
Lens is bigger than expected but light.

Could you be so kind to upload some photos outdoor from 20-40 in DNG format? Better at low ISO.
Later, of course. When you will have free time.
12-07-2013, 09:59 AM   #38
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My swimming pool... the white sky allows to test AC, and the trees for sharpness. ImageShack doesn't allow more than 5 Mbytes files so image quality is actually better than that

20 mm f2.8
http://imageshack.com/a/img560/4136/0s8u.jpg
20 mm f3.2
http://imageshack.com/a/img202/548/h8yc.jpg
20 mm f4
http://imageshack.com/a/img545/4371/nwev.jpg
30 mm f4
(slightly misfocused. To do)
40 mm f4
http://imageshack.com/a/img571/2946/pn0c.JPG

More test shots tomorrow

Cheers

12-07-2013, 10:00 AM   #39
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QuoteOriginally posted by Jonathan Mac Quote
It has a 55mm filter ring?? Pentax has never produced a lens with this size before, to my knowledge. I do love the Takumar-esque focus ring of this lens.
Yes it is a 55 mm filter thread
12-07-2013, 10:08 AM   #40
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Center sharpness test, DA 21 vs DA20-40 both at f4 on K3
Try to guess which is which...

12-07-2013, 11:19 AM   #41
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QuoteOriginally posted by goubejp Quote
Try to guess which is which.
That's tough. The second image looks very slightly weaker.
So, "unencumbered by the facts," let me guess that's the zoom.
12-07-2013, 11:20 AM   #42
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QuoteOriginally posted by goubejp Quote
Center sharpness test, DA 21 vs DA20-40 both at f4 on K3
Try to guess which is which...
Top picture is DA 21. Not as clear in focus. But I shoot the DA 21 at 5.6 and above anyway because the lens is softer at F4 and below.
12-07-2013, 11:42 AM   #43
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Left and right 100 % crops, DA20-40 at f4. Nice. The extreme right is soft, though.

12-07-2013, 11:46 AM   #44
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QuoteOriginally posted by Driline Quote
Top picture is DA 21. Not as clear in focus. But I shoot the DA 21 at 5.6 and above anyway because the lens is softer at F4 and below.
According to photozone
Pentax SMC DA 21mm f/3.2 AL Limited - Review / Lab Test - Analysis
The DA21 is very even between f4 and f5.6. My guess is that at f4 there is less diffraction than f5.6 for the K3 sensor.
There is some slight difference but not that much; and the zoom looks much better on the sides. More homogeneous.
12-07-2013, 11:49 AM - 2 Likes   #45
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DA 20-40 has arrived !!!

I have not had time to test the lens.It was dark and bad weather
The WR feature came in handy.

Photo, s one day after the storm.
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